Saw-tightener.



110.729,436. l 'PATENTED MAY26,1903, A. H. SOUTH 9 J.Y G. BOSTWIGK.

SAW TIGHTENER. APPLIOATION FILED Dnc. a1. 1992.

N0 MODEL.

` UNITED f lSTATES Ag I Patented May 26, 1903.

PATEN T OFFICE.

ALBERT H. SOUTH AND JOHN O. BOSTWICK, OF ORSON, IOWA.

lSAWTIGHTErHaR.

SPECIFICATION forming part of LettersPatent-No. 729,436, dated Mayas,1903. Application filed December 31| 1902. Serial No. 137,310. (Nomodel.)

To @ZZ whom t may concern:

Beit known that we, ALBERT H. SOUTH and JOHN C. BOSTWIOK, citizens of-the United States, and residents-of Orson, in the county" of Harrisonand State of Iowa, have invented new and useful Improvements inSaw-Tighteners, of whichthe following is a full, clear, and exactdescription.

Our' invention relates to certain novel and useful improvements insaw-tighteners, and has particular application to a device of the typementioned for tightening the saw-blades in the frame of what is commonlyknown as a bucksaw.

One of the principal objects contemplated in carrying out the presentinvention is to .produce a tightener which may be readily and easilymanipulated, whereby the saw.- blade when it is loose or slack in theframe may be brought tothe desired tension or tightness.

We also have in view the constructionofa tightener which maybe operatedWithout the'V use of the ordinary set-screWs-or the like,

whereby much time is saved, theonly acti'on necessary beingthe-operation of a swinging lever Which is connected with thefrictiongrip tightening means.

A further object of our invention is to construct a mechanism'whichshall be exceedingly simple and durable, capable of being readilyattached to the frame of the saw and removed therefrom, and one whichmay be manufactured and sold at but little expense.

With the aboverecited and other objects@ of a similar nature in viewourinven tion consistsfin'the peculiar construction, combinaf tion, and*arrangement of parts, as will .be

`part of our improved tightener.

showing the position assumed by the parts when they are in frictionallock-ing engagement; and Fig. 3 is a view similar to Fig. 2, -butshowingthe parts out of locking engagementwhereb v theY main rods of thetightener may be movedrelatively to each other.

Referring now to the accompanying draw ings, the frame of the saw, whichis clearly illustrated in Fig. 1, is of an ordinary and well-known form,comprising the horizontally-extending bar 1 and the twov approxi-'mately vertically arranged frame portions 2 and 3, the portion 3 beingrelatively longer than the portion- 2 andis formed with a handle or gripet. The saw-blade is also of any Well-known or preferred form, as shownat 5,

Vand is riveted between the vertically-extending portions 2 and 3 of theframe. The upper ends of the vertical portions 2 and 3 are preferablygrooved to receive the looped portions6 and- 7 of the rods 8 and 9,forming a As will be observed on reference to the drawings, these rodsare arranged parallel to each other in slightly-different horizontalplanes, the rod rigidly secured thereto. In the present instance therods are formed of metal, and to the end of the rod 8 is secured thebifurcated portion 11 of the lever 12, said lever extending downwardly,toward the main bar l of the saw-frame. AAs will be observed, especiallyon reference to Figs. 2 and 3, this lever 12 is pivotedat 11 to the rod8 in such manner that it ma'yreadilyoscillate or swing, the rod'9passing'between the arms forming the vbifurcation of the lever andextending parallel with the rodS a short distance-below the same. Asecond small horizontally-dis posed. bifurcated lever 13 is pivoted atone end 14 to the bifurcated portion of the main lever and is adapted topivotally receive, as at 15, the sliding block 16, which is providedwith an aperture 17, through which the rod 9 extends. A spirally-coiledtensionspring 18 is wound around the rod' 9l'lii'1termediate thebifurcated portion of the mainlever and the sliding block 16,said blockbeing preferably provided with a handle or grip 19. A

9 being provided with a clip or bracket 107 5 second sliding block 20 ispivotally secured at 21 to the end of the rod 9, said block beingsimilar in every respect to the block 16, having an aperture or bore 22for the passage of the rod 8 and a handle-grip 23. A coiled spring 24, acounterpart of the spring 18, is wound about the rod S and bears at oneend against the sliding block 2O and at the other end against thebracket 10.

From the above description, taken in connection with the drawings, theoperation of our device will be readily apparent. The frame of the saw,which, as heretofore described, is of ordinary construction, has itscentral horizontal bar so socketed in the side bars of the frame that asaw-blade held at the l'ower ends of said side bars may be tightened orloosened, as desired, by tensioning the upper ends of the side bars-thatis to say, when said ends are forced or drawn toward each other thesaw-blade will be tightened and when the ends are allowed to move awayfrom each other the lower portion of the side bars will becorrespondingly thrown inwardly and the blade loosened. In Fig. 2 wehave illustrated the position of the parts assembled by the tightenerwhen they are in locking engagement. Now if it is desired to tighten theblade the rods must be moved or slid inwardly relative to each otheruntil the distance between the looped portions islessened, and this isaccomplished by swinging the lever 12 back and forth. When the lever isswung on its pivot 1l, the frictional locking en" gagement between thewalls of the apertures 17 and 22 of the blocks 16 and 20, with theparallel rods, will be released and the rods will be fed inwardly towardeach other and the vertical sides of the frame being drawn toward eachother the blade will be tightened. When it is desired to loosen theblade, the sliding blocks may be fed inwardly toward each other bygripping the handle portion, and the rods may be moved outwardly and thedistance between these ends may be readily lengthened. The springs, itwill be observed, tend to retain the parts of the device in frictionallocking engagement when it is desired to have the same remainstationary, as when the saw is in use.

There are many other advantages incident to our improvement which willreadily be appreciated, so that it is unnecessary to describe the samein detail here.

While we have herein illustrated and described one particular embodimentof our inventon we wish it to be understood that We do not considerourselves as limited to the precise construction, as there may bemoditications and variations in certain respects without departing fromthe essential features of the invention or sacrificing any of theadvantages thereof.

Having thus described our invention, we

claim as new and desire to secure by Letters Patent- 1. A saw-tightenercomprising two rods, means slidably mounted on each of said rods andnormally resting in frictional contact therewith, and a device forslidingthe means of one rod along the same and simultaneously drawingthe other rod inward, the construction being such that the rods will bemoved toward each other, substantially as set forth.

2. A saw-tightener comprising two rods movable relatively to each other,block for each of said rods slidably' mounted on and frictionallyengaging therewith, tension means for normally pressing each block infrictional contact with its rod, and a device connected with one of saidrods and with the sliding block of the other rod, the construction beingsuch that when said device is actuated the rods will be moved towardeach other, substantially as set forth. l

3. A saw-tightener comprising two rods movable relatively to each otherand formed with loops at their outer ends, said loops being designed tot over the bars of the sawframe, a clip secured to one of said rods anddesigned to act as a guide'for the other rod during its movement, alever secured to the opposite rod from that carrying the clip, a slidingblock mounted on and frictionally engaging with each of said rods, and aconnection between the lever and one of said blocks, and the lever andone Vof the rods, the con-y struction being such that when the lever isactuated the rods will be moved inward toward each other, substantiallyas set forth.

4. The combination with a saw-frame and a blade mounted therein, of atightener therefor, said tightener comprising two rods adapted to engagethe frame of the saw, a lever pivoted to the end of one of said rods, ablock slidably mounted on the other rod, a pivotal connection betweenthe lever and said block, and a second block slidably mounted on the rodto which the lever is pivoted, the construction being such that theblocks are adapted to be normally held in frictional contact with saidrods to lock the same against movement, but will permit the rods to bemoved toward each other when -the lever is actuated.

5. The combination with a saw-frame, a blade mounted therein and atightener therefor, the latter comprising rods secured to the saw-frame,and arranged in parallelism, a main lever pivoted to the end of one ofsaid rods, a sliding block pivoted to the end of the opposite rod andslidable along the firstmentioned rod, a second sliding block movable onthe second rod, a link connection be tween the last-mentioned block andthe 1ever, a clip on one of said rods, a spring interposed between theadjacent sliding block and the clip, and a second spring interposed IOCIIO

between the main lever and its adjoining names to this specification inthe presence of sliding block, the construction being such twosubscribing Witnesses. that when the main lever is actuated the rodsALBERT H. SOUTH.

will be moved relatively to each other foil x JOHN C. BOSTWICK. 5tightening the saw-blade in the frame, sub- Witnesses:

stantially as set forth. B. S. LONG,

In testimony whereof We have signed ouil J. C. REEVES.

